package juc;
/*
* 模拟CAS 算法
* */
public class TestCompareAndSwap {
    public static void main(String[] args) {
        final  CompareAndSwap cas = new CompareAndSwap();
        for (int i = 0; i < 10; i++) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    int exceptedValue = cas.getValue();
                    boolean b = cas.compareAndSet(exceptedValue, (int) (Math.random() * 101));
                    System.out.println(b);
                }
            }).start();

        }
    }
}
class CompareAndSwap {
    private int value; //内存值

    //获取内存值
    public synchronized int getValue() {
        return value;
    }

    //
    public synchronized int compareAndSwap(int expectedValue, int newValue) {
        int oldValue = value;
        if(oldValue == expectedValue) {
            this.value = newValue;
        }
        return oldValue;
    }

    //比较
    public synchronized boolean compareAndSet(int expectedValue, int newValue) {
        return expectedValue == compareAndSwap(expectedValue, newValue);
    }
}
